Mouse click and drag to paint (previous paints will fade slightly).
Color and size are based on mouse position.
SPACE - paint without fading previous actions
RIGHT/LEFT - increase/decrease rotation of letters
R - reset rotation to 0
z|Z - shift canvas right|left 10 px
x|X - shift canvas up|down 10 px
f|F - flip canvas horizontally|vertically
123456 - preset painting macros
UP/DOWN - change paint mode (TODO: change keys)
M - switch between grids and circles (TODO: change keys)
Delete|Backspace - clear the screen
S - Save